Wireless Communication Apparatus and the Method Thereof

1. A wireless communication apparatus, transmitting at least one data by using a plurality of sub-carriers, the wireless communication apparatus comprising: a signal modulator, configured to generate at least one modulated signal in time domain based on the at least one data; a signal processor, coupled to the signal modulator, and configured to perform signal processing on the at least one modulated signal, wherein the signal processor comprises a window module and a filter module, wherein the window module performs windowing operation on the at least one modulated signal to generate a window-operated signal, and the filter module performs filtering operation on the window-operated signal to generate a transmitting signal in time domain; a storage, storing a plurality of program codes; a computing processor, coupled to the signal processor and the storage, and configured to access the program codes to perform operations of setting up the window module and the filter module respectively according to a window characteristic function and a filter characteristic function, and perform operations of performing an iterative out-of-band power leakage suppressing algorithm, wherein the iterative out-of-band power leakage suppressing algorithm is to estimate the window characteristic function and the filter characteristic function based on an out-of-band power spectral density function; and a transmitter, coupled to the signal processor and configured to transmit the transmitting signal.

2. The wireless communication apparatus of claim 1 , wherein the computing processor is configured to receive a plurality of system parameters, and the out-of-band power spectral density function is based on the system parameters, wherein the system parameters comprise the filter characteristic function, a length of the filter characteristic function, the window characteristic function, a length of the window characteristic function, and a quantity of the sub-carriers.

3. The wireless communication apparatus of claim 1 , wherein the storage further stores a plurality of candidate window characteristic functions and a plurality of candidate filter characteristic functions, and the computing processor accesses the program codes to perform operations of: setting up the window module and the filter module according to one or more condition parameters, the window characteristic function of the candidate window characteristic functions and the filter characteristic function of the candidate filter characteristic functions.

4. The wireless communication apparatus of claim 3 , wherein the computing processor is configured to receive the one or more condition parameters and accesses the program codes to perform operations of: according to the one or more condition parameters, selecting the window characteristic function from the candidate window characteristic functions and selecting the filter characteristic function from the candidate filter characteristic functions, wherein the one or more condition parameters comprise at least one of out-of-band power leakage suppression level and signal-to-noise ratio loss.

5. A wireless communication apparatus, transmitting a plurality of data by using a plurality of sub-carriers, the wireless communication apparatus comprising: a signal modulator, configured to generate a plurality of modulated signals in time domain based on the data; a plurality of signal processors, coupled to the signal modulator, and configured to perform signal processing on the modulated signals, wherein each signal processor comprises: a window module, configured to perform windowing operation on one of the modulated signals to generate a window-operated signal, and a filter module, configured to perform filtering operation on the window-operated signal to generate a transmitting signal in time domain; a storage, configured to store a plurality of program codes; a computing processor, coupled to the signal processors and the storage, and configured to access the program codes to perform operations of setting up the window modules and the filter modules of the signal processors respectively according to a plurality of window characteristic functions and a plurality of filter characteristic functions; and at least one transmitter, coupled to the signal processors and configured to transmit the transmitting signals generated by the signal processors.

6. The wireless communication apparatus of claim 5 , wherein the computing processor accesses the program codes to perform operations of performing an iterative out-of-band power leakage suppressing algorithm based on an out-of-band power spectral density function to estimate the window characteristic functions and the filter characteristic functions.

7. The wireless communication apparatus of claim 6 , wherein the computing processor is configured to receive a plurality of system parameters, and the out-of-band power spectral density function is based on the system parameters, wherein the system parameters comprise the filter characteristic functions, a length of the filter characteristic functions, the window characteristic functions, a length of the window characteristic functions, and a quantity of the sub-carriers.

8. The wireless communication apparatus of claim 5 , wherein the storage further stores a plurality of candidate window characteristic functions and a plurality of candidate filter characteristic functions, and the computing processor accesses the program codes further to perform operations of: setting up the window modules and the filter modules of the signal processors according to one or more condition parameters, the window characteristic functions of the candidate window characteristic functions, and the filter characteristic functions of the candidate filter characteristic functions.

9. The wireless communication apparatus of claim 8 , wherein the computing processor is configured to receive the one or more condition parameters, and further accesses the program codes to perform operations of: selecting, according to the one or more condition parameters, the window characteristic functions from the candidate window characteristic functions, and the filter characteristic functions from the candidate filter characteristic functions, wherein the one or more condition parameters comprise at least one of out-of-band power suppression level and signal-to-noise ratio loss.

10. A method of generating wireless signals, applied to a wireless communication apparatus transmitting at least one data by using a plurality of sub-carriers, the method comprising: setting up a signal processor of the wireless communication apparatus according to a window characteristic function and a filter characteristic function; generating at least one modulated signal in time domain based on the at least one data; performing windowing operation on the at least one modulated signal to generate at least one window-operated signal, and performing filtering operation on the at least one window-operated signal to generate at least one transmitting signal in time domain, further comprising: performing, based on an out-of-band power spectral density function, an iterative out-of-band power leakage suppressing algorithm to estimate the window characteristic function and the filter characteristic function; and transmitting the at least one transmitting signal.

11. The method of claim 10 , wherein the out-of-band power spectral density function is based on a plurality of system parameters, wherein the system parameters comprise the filter characteristic function, a length of the filter characteristic function, the window characteristic function, a length of the window characteristic function, and a quantity of the sub-carriers.

12. The method of claim 10 , wherein estimating the window characteristic function and the filter characteristic function by targeting at decreasing the function values of the out-of-band power spectral density function to a pre-defined level.

13. The method of claim 10 , wherein the step of performing the iterative out-of-band power leakage suppressing algorithm to estimate the window characteristic function and the filter characteristic function comprises: estimating an initial window characteristic function by targeting at decreasing the function values of the out-of-band power spectral density function; updating the out-of-band power spectral density function based on the initial window characteristic function and estimating an Nth iterative filter characteristic function by targeting at decreasing the function values of the out-of-band power spectral density function, wherein N is a positive integer; updating the out-of-band power spectral density function based on the Nth iterative filter characteristic function, and estimating an Nth iterative window characteristic function by targeting at decreasing the function values of the out-of-band power spectral density function; updating the out-of-band power spectral density function based on the Nth iterative window characteristic function and, estimating an (N+1)th iterative filter characteristic function by targeting at decreasing the function values of the out-of-band power spectral density function; updating the out-of-band power spectral density function by substituting the (N+1)th iterative filter characteristic function into the out-of-band power spectral density function and estimating an (N+1)th iterative window characteristic function by trimming down the value of the out-of-band power spectral density function; and calculating a mean square error between the (N+1)th iterative window characteristic function and the Nth iterative window characteristic function, and a mean square error between the (N+1)th iterative filter characteristic function and the Nth iterative filter characteristic function; wherein when the mean square error between the (N+1)th iterative window characteristic function and the Nth iterative window characteristic function is not greater than a threshold value and the mean square error between the (N+1)th iterative filter characteristic function and the Nth iterative filter characteristic function is not greater than the threshold value, the (N+1)th iterative window characteristic function is determined to be the window characteristic function and the (N+1)th iterative filter characteristic function is determined to be the filter characteristic function; wherein when the mean square error between the (N+1)th iterative window characteristic function and the Nth iterative window characteristic function is greater than the threshold value or the mean square error between the (N+1)th iterative filter characteristic function and the Nth iterative filter characteristic function is greater than the threshold value, the out-of-band power spectral density function is updated based on the (N+1)th iterative filter characteristic function, and an (N+2)th iterative window characteristic function is estimated by targeting at decreasing the function values of the out-of-band power spectral density function.

14. The method of claim 13 , wherein the initial window characteristic function, the Nth iterative filter characteristic function, the Nth iterative window characteristic function, the (N+1)th iterative filter characteristic and the (N+1)th iterative window characteristic function are estimated by targeting at decreasing the function values of the out-of-band power spectral density function to a pre-defined level.

15. The method of claim 10 , further comprising: selecting, according to one or more condition parameters, the window characteristic function from a plurality of candidate window characteristic functions, and the filter characteristic function from a plurality of candidate filter characteristic functions.

16. The method of claim 15 , wherein the one or more condition parameters comprise at least one of out-of-band power suppression level and signal-to-noise ratio loss.